Nature

Hot & Humid Monsoon Gardening

Red Amaranth

During a recent road trip I was fortunate enough to have the opportunity to visit an American landmark that I had wanted to visit for many years – the Mitchell Corn Palace of Mitchell, South Dakota. The exterior of the Corn Palace is adorned with decorative murals that are constructed almost entirely of corn kernels. It takes over 100 acres of plants to provide enough corn to complete the murals. Each year a new theme is selected for the murals and they are taken down and replaced, this year’s theme was “Remember When.”

It may seem odd to have a palace dedicated to and built from corn, but for a Southwestern gardener like me, a palace dedicated to corn seems very appropriate considering corn’s importance in our region – both historically and today.

Corn has been grown in the Americas for thousands of years as a staple food crop for the Native Americans that domesticated it. Today, when most people think of corn they picture a steaming sweet yellow cob that often accompanies meat and potatoes at summer barbecues. In all actuality this type of sweet corn is a relatively new discovery, botanically speaking. The majority of corn grown both historically and today is used as feed for livestock or as a base ingredient for any number of food and non-food products. It is estimated that it takes 25 corn plants per person per day to maintain the American way of life.

Here in the southwest, tribes such as the Tohono O’odham, Quechan, and Gila perfected varieties of dent, flint, pop and sweet corns that grow exceptionally well when planted along with the heavy monsoon rains that occur this time of year. Tohono O’odham 60 Day, Yuma Yellow and Gila Pima “A:al Hu:n” are just a few of the many varieties of corn that grow well when planted with our summer rains. Other varieties to consider are Golden Bantam 8 Row, Golden Bantam 12-Row and Hopi Blue.

Along with corn, a wide variety of edible crops have been domesticated to grow and thrive in the hot and humid conditions that are characteristic of the monsoon. The main benefit of growing native crops that are indigenous to our area is that they are already acclimated to our extreme weather conditions; however there are several added benefits. First among them is that many of our native crops are highly nutritious. Amaranth, for example, is often touted as the next super food for its high nutrient content. My favorite variety of amaranth is Hopi Red Dye for the color it brings to the summer garden, but you will also have success growing the varieties Mayo Grain and Alamos.

Another benefit of planting a monsoon garden of native crops is that they are often very different than what is commonly available at grocery stores and farmer’s markets. This variety will bring a little excitement to your culinary experiments. Tepary beans are highly nutritious and the most drought tolerant of any bean. Tests have shown that they can subsist without any external irrigation whatsoever. For gardeners in cooler parts of our region, the Bolita bean is a great substitute for the common pinto bean as they taste better, cook faster and have a creamier texture. Other crops to consider for your monsoon vegetable garden include cowpeas, okra and watermelon.

When planning for your monsoon garden keep in mind that although the crops discussed above generally thrive during this hot and humid season, they still need to be planted in such a way that that they are able to take advantage of short bursts of heavy rain. Planting in a sunken bed or basin is the traditional growing method for a monsoon garden. Designing your garden in this way will help to conserve as much rain water as possible. If possible, rain water should be directed from your roof or any other catchment to the garden where it will do the most good. Your garden will also benefit immensely if you incorporate other organic gardening principles such as intensive spacing, companion planting and mulching into your plans.

All of the seed varieties listed above can be found online at NativeSeeds.org or by visiting the Native Seed/SEARCH retail store at 3601 N. Campbell Ave. Brandon Merchant is the proprietor of Southwest Victory Gardens. Visit his website at SouthwestVictoryGardens.com.

Coping with Summer Pests

There is nothing more reminiscent of summer in Southern Arizona than the sound of cicadas buzzing away in the heated stillness. This pleasant humming provides the soundtrack for summers in our region and for those of us who have lived here our entire lives, their return is often a cause for celebration. For vegetable gardeners, the return of the locust is often a bittersweet moment because with it marks the return of a wide variety of insect pests that like to make our summer vegetable gardens home.

Considering that Arizona is home to over 13,000 unique insect species, with many more yet to be discovered, it should come as good news that only a small fraction of these can cause harm to plants in the vegetable garden. Of the three dozen or so that can become a nuisance, only a small percentage require diligence on the part of the gardener to keep them under control. Fortunately, a lot of research has gone into developing control methods for the most destructive backyard garden pests.

Many gardeners shiver at the first appearance of an unknown insect in the garden. Perhaps it’s an innate fear of insects they developed as a child, or perhaps it is effective marketing on the part of poison pushers like pest control companies and pesticide manufacturers. Regardless of the reasoning, the fear is most often a result of a misunderstanding and not grounded in reality. In reality, most insects are harmless and it takes an awful lot of neglect on the part of the gardener to let the damage caused by insects to reach a point that can actually harm garden plants.

Tobacco hornworm, larva of Manduca sexta, on a cherry tomato plant.
photo: Wikimedia Commons

Another reality often overlooked or ignored by gardeners is the fact that the presence of insects, even pest insects, does not necessarily indicate a problem and in fact some of the “damage” caused by these insects can actually be quite beneficial to the plants which are afflicted. Tomato hornworms, for example, perform a great pruning service if not left to take over and can actually encourage new growth of tomato plants. Although they may not do the job exactly as a trained professional would, you can rest assured knowing that your plants will be much better off than the plants down the street that were treated with a toxic pesticide.

The most common response from gardeners when faced with the hornworm or any other leaf chewing caterpillar is to first freak out, and then second to reach for the closest pesticide to deal with the “problem.” Once this cycle is started it is very difficult to get out of. After the adult caterpillars are eliminated, any predatory wasps that may depend on them for breeding will also end up leaving, which in turn can result in the appearance of an even greater number caterpillars in the future. As the cycle progresses, more applications of pesticides are required and the problem is exacerbated.

It may not seem beneficial at first, but there are many positive aspects to the presence of a few pest insects in the garden. As soon as pest insects begin to arrive, it also signals the return of their natural predators. When drastic measures are taken to eliminate the pests, we often unknowingly also eliminate the many predators which naturally keep those pests at bay. These can be insect predators such as the ubiquitous green lacewing or even larger predators such as birds. More often than not, gardeners are too quick to resort tactics that will alter or even eliminate the delicate ecosystem needed to grow a healthy garden.

So what is a gardener to do? No one, including myself, wants to give their garden over to bugs when so much time, work and money have gone into producing a crop. The trick is to approach the situation with a good attitude and to take the least invasive steps possible to eliminate the problem. Although not an instant fix, when basic initial steps are taken we can begin to create a garden environment that is both inhospitable to pest insects and attractive to beneficials.

The first step is to provide your plants with a proper growing environment that meets or exceeds their nutritional requirements. Sickly, malnourished, or drought stricken plants actually attract pest insects while healthy plants actually repel them. Well cared for plants will also bounce back quicker from an attack than those that may be lacking in nutrients. Infestations will rarely occur in a healthy garden. Further steps can be taken to reduce the chance of a pest outbreak. Timing your plantings so that your crops will be well established by the time pests arrive is very effective. A sprawling squash plant will send out roots all along the vine so that if a vine borer severs the main stem the plant will still survive.

Furthermore, by planting cultivars that are already resistant to the most common pests in our region, we can almost eliminate the chance of attack all together. A good example would be butternut and acorn squash, which both are resistant to squash vine borer attack. Further control can be achieved when organic gardening methods are incorporated into your garden plan. The most successful techniques include interplanting of pest repellant plants amongst the garden or even dedicating a small area of the garden to plants that will provide a habitat for beneficial insects.

These methods take time to work and are not instantaneous, but when combined with due diligence on the part of gardener, then the likelihood of your garden being invaded will be greatly reduced. While not as satisfying as emptying a can of Raid, in the long run you and your garden will be much healthier.

Brandon Merchant is the proprietor of Southwest Victory Gardens. Visit his website at SouthwestVictoryGardens.com.

Plant a Square Foot Garden

Those of us who have been gardening in the Southwest for more than a few seasons have probably come to learn that the advice found in most gardening books and magazines just doesn’t work in our climate. One of the first lessons learned comes from following generic planting recommendations printed on seed packets. The planting dates for our area are usually wrong and the recommendations often call for planting in long, mounded rows.

In other parts of the country, where rain and space is plentiful, row planting makes sense. Here in Tucson however, planting this way can lead to thirsty plants.  But even after converting to basin-style gardening, which is more appropriate for our area, many gardeners still continue to plant in row fashion by scattering large amounts of seeds along shallow trenches. Not only is this technique wasteful, but it leads to more work and crowded plants.

An example of square foot gardening at The Garden Kitchen in South Tucson, where Brandon Merchant teaches classes once a month.
photo: Brandon Merchant

Fortunately, there is an alternative to row planting that will not only save you time, but will also allow for increased yields while reducing the need for weeding and the amount of water required to keep your garden healthy. I’m speaking of the square foot gardening method; a system that was developed by civil engineer Mel Bartholomew in the 1980s.

Unlike row planting, square foot gardening involves creating small but densely planted gardens with the goal of maximizing yields from smaller spaces. The technique borrows heavily from earlier sustainable agriculture methods such as French intensive planting and biointensive agriculture, but it is designed for the relatively small backyard vegetable garden.

Any garden space can be converted into a square foot garden by following a few simple steps. First, in order for vegetables to be planted densely using the square foot method, your soil must be heavily amended or even replaced with a nutrient-dense growing medium. The most common medium is a mixture of compost, coco coir and vermiculite. This mixture of ingredients provides the perfect balance of nutrients, water holding capacity and soil aeration that densely planted gardens thrive in.

The ratio at which these ingredients are mixed can be adjusted to fit your garden and your budget. In the bestselling book Square Foot Gardening, Mel Bartholomew recommends an even mix of 33% of each ingredient; however these are only recommendations and need not be followed to a T.

Although the soil mix is very important, what ultimately defines a square foot garden is the layout. Prior to planting, the garden is first divided into one foot by one foot squares. You can do this easily by using garden twine and tent stakes, or if you’re feeling industrious you can make a more permanent grid using lumber.

Within each square of the grid, crops are planted in a pre-defined pattern. For example, in one square foot you could either plant nine turnips, 16 carrots or one eggplant. Every square foot has a maximum number of each crop that can be planted in it. Although it is not necessary to plant the recommended maximum number of plants, you should never exceed the recommendation. When planting from seed, great care should be taken to not over plant; two or three seeds per hole are usually sufficient. What may seem like a meticulous task at first will save you time in the long run.

Square foot gardening can also be combined with organic gardening techniques such as succession planting, intercropping, cover cropping, and companion planting.  Crops with similar square foot growing requirements can be combined for more effectiveness. For example, one square foot could hold a mixed combination of 16 radish and carrots.

There are many square foot garden planting guides available online for free or you can learn more by picking up a copy of Square Foot Gardening at your local book store or library. Another great way to learn how to properly plan your square foot garden is to subscribe to an online garden planner service such as GrowVeg.com or the Mother Earth News online garden planner. Each of these programs offers a free 30 day trial and both allow users to create their own unique garden plans using the square foot gardening method.

Brandon Merchant is the proprietor of Southwest Victory Gardens. Visit his website at SouthwestVictoryGardens.com.